Yankee Adhesive Composition for Tissue Transfer
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Solution Overview
Problem
Existing Yankee adhesives face challenges in achieving a narrow operating window for efficient transfer and removal of high bulk tissue webs without web breakage, while also ensuring high production capacity and easy dissolving of tissue products.
Innovation Solution
A Yankee adhesive composition using a high molecular weight polyvinyl alcohol (PVOH) solution with a viscosity range of 175.0 - 225.0 cP, combined with a release agent, applied at a total add-on of 15-35 mg/m², which improves wet tack transfer and reduces adhesive penetration into the web, facilitating easier take-off and faster dissolving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional Yankee adhesives are used to transfer high bulk tissue webs, then web transfer stability is improved, but web breakage occurs during take-off and production capacity is limited
Solution Approach 1:
The patent changes the molecular weight parameter of PVOH from conventional ranges to very high molecular weight (1,000,000-10,000,000 g/mol), which fundamentally alters the adhesive's viscoelastic properties. This parameter change enables the adhesive to provide sufficient wet tack for web transfer while maintaining elasticity for easy take-off, thus resolving the contradiction between reliability and productivity
Solution Approach 2:
The patent creates a composite adhesive system combining very high molecular weight PVOH with specific additives including polyethylene glycol (PEG), polypropylene glycol (PPG), and optional crosslinking agents. This composite formulation synergistically provides both strong initial adhesion for web transfer and controlled release for take-off, enabling high production capacity without web breakage
2Reliability
If adhesive is applied to improve web transfer, then wet tack effect is improved, but adhesive penetration into web increases causing dissolving problems
Solution Approach 1:
The patent changes the concentration parameter of the adhesive solution to a very low range (0.1-1.0%, preferably 0.3-0.7%), which significantly reduces adhesive penetration into the web while maintaining sufficient wet tack effect. This low concentration combined with very high molecular weight PVOH ensures minimal adhesive residue that would interfere with web dissolving
Solution Approach 2:
The patent applies adhesive only in the specific local area where web transfer is needed (on the Yankee dryer surface), rather than throughout the entire web structure. This localized application minimizes adhesive penetration into the web bulk while providing sufficient tack at the transfer interface
3Productivity
If tissue web speed is increased to improve production capacity, then productivity is improved, but web breakage occurs during transfer and take-off
Solution Approach 1:
The patent uses very high molecular weight PVOH which provides dynamic, time-dependent adhesion characteristics. The adhesive exhibits strong initial tack for immediate web pickup at high speeds, then transitions to elastic behavior that accommodates web tension changes during high-speed operation, preventing web breakage while maintaining productivity
Solution Approach 2:
The patent optimizes the molecular weight parameter to very high ranges (1,000,000-10,000,000 g/mol) which fundamentally changes the adhesive's mechanical response time. This enables the adhesive to keep up with high-speed web transfer while maintaining web integrity, resolving the contradiction between productivity and reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances production capacity, produces uniform tissue rolls with improved dissolving properties, reducing adhesive residue and preventing sewer pipe blockages, while maintaining a uniform roll diameter and reducing adhesive consumption.
Implementation Method 1
provide a wet tack effect sucking the moist web onto the Yankee surface
Implementation Method 2
facilitate the even removal by the doctor blade of the finally dried web from the surface of the Yankee
Implementation Method 3
Final drying is obtained by evaporation on a Yankee dryer
Implementation Method 4
toilet paper to be able to be dissolved quickly when discarded in a water closets
Data Source
Figure 1
Figure 2a~2b
Figure 2c~2d
AI summary
The invention relates to a method of transferring a tissue web with residual moisture to a Yankee cylinder and final removal of the dried tissue web from the Yankee cylinder using a doctor blade and collecting the dried web on a reel-up machine forming a tissue reel. The invention also relates to the Yankee adhesive composition per se. The method involves preparation of a water solution of a Yankee adhesive composition with less than 10% final solids content to be applied on the surface of the Yankee cylinder ahead of transferring the tissue web with residual moisture to the Yankee cylinder. The inventive method applies an aqueous PVOH solution with a very high molecular weight polyvinyl alcohol as a part of the solid content of the Yankee adhesive in an amount ranging from 20-65% of the final solids content of the Yankee adhesive. The aqueous PVOH solution with the very high molecular weight polyvinyl alcohol establish a viscosity ranging from 90 cP to 300 cP.